Various devices have been proposed to measure material properties. For instance, WO 2012/015592 reports a probe-based device that performs reference point indentation without a reference probe. The indentation distance is measured relative to the instrument which remains substantially stationary during the impact process, which occurs on the order of one millisecond. In one embodiment, an impact motion with a peak force of order 40N creates an indentation in bone with a depth of approximately 150 μm during which the instrument case moves less than 1 μm. Thus the error in measuring indentation depth due to the motion of the case is less than 1%, making a reference probe unnecessary.
Despite the various proposed devices, a need still exists in the art for novel material measuring probes, devices and methods.